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the latter they are separated by the beak being hooked, and the absence of a bony
temporal arch to the skull. In the box-tortoises the head is covered with smooth
skin above, the toes having only a rudimental web, and the tail is short. The
Carolina box-tortoise (Cistudo Carolina) is a somewhat variable species as regards
si/e, the length of the shell ranging from a little over 4 to somewhat more than
5 inches. The highly convex carapace is almost hemispherical in shape, and is



BOX-TORTOISES. 67

ttached to the plastron solely by ligament, so that the whole shell can be com-
stely closed. As a general rule, the upper shell is dark brown or blackish, with
11. .w >p<>t-. or brownish yellow, with dark brown spots or rays, while there
\\ ! an interrupted yellow streak down the middle of the back. The plastron
ly be either a uniform dark brown or blackish, or may have irregular yellowish
jtches on a ground of the same, while in some instances it is yellowish with dark
jtches of variable size. The range of this species embraces the Southern and
juth-Eustern United States and Mexico. In the ornate box-tortoise, from
jbraska and some neighbouring states, the shell is more depressed, and the



^r- ^i I ^ ^VS^Cv. '.i-A.'^iv \ \







CAROLrxA BOX-TORTOISE (\ nat size).



68 TORTOISES AND TURTLES.

herons are in the habit of nesting, owing to the quantity of insects, snails, worms,
and fragments of fish to be met with in such localities ; and they are frequently
found in woods where the ground is cither moist or swampy. At times
they will, however, enter the water of their own free will: and they have lieen
seen half-buried under loose earth or moss in search of worms and insects.
Unlike most members of the family, the box-tortoises shun the light, and are most
active during the evening and night, shutting themselves closely up in their shells
when the sun is shining brightly. The closure of the shell is also effected at the
approach of any large animal ; and when thus securely boxed up, there are but
few creatures these tortoises need fear. Like most other terrestrial tortoises, the
females lay their eggs in holes dug in the ground by themselves ; the number laid
being usually only five or six, whether the parents be half-grown or adult. Each
individual egg is carefully covered with earth ; the time taken before the young
are hatched being said to vary from eighty-eight to a hundred days. When first
hatched, the young are well developed, and of great relative size and strength :
although their shells are still soft and cartilaginous, and the remnant of the yolk-
sac depends from the plastron. In Pennsylvania both young and old bury them-
selves deep in the ground about the middle of October, where they remain till the
latter part of April ; the spot selected having a dry soil, and being protected from
the cutting blasts of the north. Many individuals which have not buried
themselves sufficiently deeply, are, however, frozen to death during the winter
slumber. On account of the strong and disagreeable flavour of their flesh,
doubtless engendered by the nature of their food, the box-tortoises are not eaten.

In marked contrast to the vaulted and abruptly -descend ing
carapace of the box -tortoises, is the depressed and shelving shell
of the pond-tortoises; this difference indicating a distinction in the habits of
the two genera. Thus whereas the box-tortoises are, as we have seen, mainly
land reptiles, the pond -tortoises are as decidedly aquatic in their mode of
life. In addition to the difference in the form of the shell, the members of
the present genus are readily distinguished from those of the last by the
beak not being hooked, and by the presence of a bony temporal arch in the
skull. In the shell the carapace is united to the plastron solely by ligament,
while the plastron itself is more or less distinctly divided by a ligamentous
transverse hinge, upon w r hich its two lobes are movable. Agreeing with the
box-tortoises 'in having the top of the head covered with undivided skin, the
pond -tortoises differ by having the toes fully webbed, and also by the moi
elongated tail, which, while very long in the j^oung, is of moderate length in tlu
adult. Although the genus Emys was formerly made to include many of tin
fresh-water terrapins, it is now restricted to the European pond-tortoise (E. orl>i-
cularis), and a nearly allied North American species. The former, which is
familiar to most visitors to Southern Europe, is characterised by the short oval
form of its carapace, which is widest posteriorly, and in the young state has a
more or less distinct median keel. In colour, the upper shell of the adult is. dark
brown or black, ornamented with a variable number of light, usually yellow, dots
or radiating streaks ; the plastron being either yellow, brown and yellow, or
almost wholly blackish brown. In the young, however, the upper shell is dark



POND- TOR TOISES.



69



brown, and the lower black ; all the shields of the latter, as well as the marginal
OIK'S of the former, having a large yellow .spot. The skin of the head, neck, body,
and limbs is marked with yellow and blackish, in varying porportions ; the head
of the male having brownish dots on a darker ground, while in the female the dots
an- yellow. When fully grown, the shell attains a length of 7^ inches, but in
most of the specimens imported into England it is not much more than half that
si/e. At the present day the pond-tortoise is found, in suitable localities, in South
and East Central Europe, and South-Western Asia as far as Persia, and in Algeria.




EUROPEAN POND-TORTOISE (f nat. size),

During the Pleistocene period, when the climate of Northern Europe must at certain
times have been much more genial, the pond-tortoise had a much more extensive
distribution, its fossilised remains having been found in the superficial deposits of
Belgium, Denmark, Cermany, Lombardy, Norfolk, Sweden, and Switzerland The
American species, which inhabits the north-eastern United States and Canada,
has the carapace rather more elongate, and the tail shorter ; the former being
black with pale yellow or brownish circular spots, and the plastron yellow with
a large black patch on each shield.

The European species inhabits both stagnant and running waters, and may be



7 o TORTOISES AND TURTLES.

found alike in slow or swift-flowing streams, or in open lakes. During the day-
time it leaves the water to bask in the sun on sequestered spots of the banks,
where it remains without moving by the hour together, but towards sunset it
begins to move, and remains active throughout the night. At the commencement
of winter it constructs an underground chamber, in which it remains buried in
slumber till spring, usually reappearing, if the weather be favourable, about the
middle of April ; at which time it reveals its whereabouts by a peculiar whistling
cry characteristic of the breeding-season. An excellent swimmer and diver, the
pond-tortoise disappears beneath the water at the slightest sound ; while when on
land its motions are far more active than those of the true tortoises. Agreeing
with other carnivorous terrapins in the absence of a median ridge on the fore-part
of the palate, this tortoise feeds chiefly upon worms, water-insects, crustaceans,
frogs, newts, tadpoles, and fish. In devouring fish, they reject the air-bladder,
which floats on the surface of the water ; and from the number of such floating
air-bladders some idea may be formed as to whether a pond is numerously
tenanted by these tortoises. In captivity, where they will live for years, pond-
tortoises, in addition to their natural food, will readily eat raw meat ; and in this
state they frequently become so tame as to take food from the hands of their
masters. The eggs, varying from nine to fifte.en in number, are laid at night
during May in hollows dug by the female in dry soil, at a considerable elevation
above the bank, where they are carefully covered up and left to develop. These
tortoises are eaten by the inhabitants of all the countries in which they occur.

The remaining members of this extensive family, which may be

Term Dins

collectively known as terrapins, and can receive but brief mention,
have the plastron without any transverse hinge, and firmly connected by bone with
the carapace, so that the whole shell is solid and immovable. They comprise a large
number of species, arranged under eleven genera, and all that can be attempted in a
work of the present nature is to select for special notice one or more species of such
genera. Although many of these terrapins are exceedingly unlike one another ex-
ternally, yet they are all so closely connected that the genera can only be dis-
tinguished by the characters of the skull and the bony plates of the shell, so that
our description must of necessity be somewhat technical.

sculptured The sculptured terrapin (Clcmmys insculpta), of eastern Nortl

Terrapin. America, is selected as a fairly well-known representative of a gem
of eight species. This genus, it must be premised, forms one of a group of four
agreeing with the two last noticed in the absence of a longitudinal ridge on tht
fore part of the palate, and in the carnivorous habits of its various membei
From the three allied genera, Clemmys may be distinguished by the aperture of tin
inner nostrils in the skull being situated between the eyes, by the unpaired
entoplastral bone of the lower shell being traversed by the groove formed by the
junction between the humeral and pectoral shields, and by the upper part of tht
head being covered with a continuous smooth skin. The figured species belongs
a group of five, characterised by the median union of the anal or hindmost shield
of the plastron being longer than that between the femoral shields: and while four
species of this group are confined to North America, Beale's terrapin (6*. 6cW< /).
inhabits China, thus showing a distribution analogous to that of the alligators. On



TERRAPINS. 7 ,

the other hand, the Caspian terrapin (C. caspica), ranging from the Caspian Sea to
the Persian Gulf, the Spanish terrapin (C. leprosa), of Spain and North- Western
Africa, and the Japanese terrapin (G. japonica), resemble one another in having the
median union of the anal shields shorter than that of the femorals. The sculptured
terrapin, which attains a length of about 7 inches, is specially characterised by the
toes being webbed only at their bases, by the upper jaw having a notch in the
middle, on the sides of which are a pair of tooth-like projections, and by the
serration of the hinder border of the carapace. The shell is much depressed, with
a raised keel down the middle of the back, and the shields of the carapace orna-
mented with the radiating and concentric strias from which that species takes its name.




SCULPTURED TERRAl'IN (| liat. size).



While the ground-colour of the carapace is blackish, the radiating lines are yellow ;
the plastron being yellow, with a large black blotch on each of its shields. The soft
parts are dark brown or olive, the sides of the head being speckled with red.
The figured species is exceedingly abundant on the Atlantic side of the United
States, from Maine to Pennsylvania and New Jersey. Frequenting both marshes
and rivers, it leaves the water for much longer periods than its European congeners,
and is sometimes found for months at a time in perfectly dry places. In wandering
from one stream to another, it makes regular tracks through the woods, and is
hence frequently termed in America the wood-terrapin. In its feeding and general
mode of life, this terrapin presents no features distinguishing it from other
carnivorous kinds.



TORTOISES AND TURTLES.



Thick-Necked Nearly allied to the preceding is tin- thick-necked terrapin

Terrapin. (]{/<//;</ cras&icollis), from Tenasseriin, Siam, the Malay Peninsula, and
Sumatra, which, with a second species from Borneo, constitutes a genus dis-
tinguished by the greater development of the bony buttresses connecting the upper
with the lower .shell, and by the hinder part of the head being covered with .small
horny shields. The feet are fully webbed, and the anterior vertebral shields of the
carapace are more or less distinctly balloon-shaped. The typical species measures
rather more than (U inches in length; and is of a general dark brown or black
colour, usually with some yellow markings on the plastron, and some large spots
of the same colour on the head. Several representatives of this genus are met
with in a fossil state in the Pliocene deposits of North- Western India.

Hamilton's The handsomely coloured Hamilton's terrapin (Damonia ///nil-

Terrapin. toni), from India, conspicuous for its black and yellow, highly

vaulted, and three-keeled carapace, is the best known representative of a third

genus, distinguished from the foregoing by the
hinder aperture of the nostrils opening behind
the line of the eyes, and the great breadth of
the palate. Like the two preceding genera, the
entoplastral bone of the plastron is traversed by
the groove formed by the union between the
humeral and the pectoral shields ; and the hinder
part of the head is covered with small shields.
Hamilton's terrapin has the elevated carapace
marked with three interrupted longitudinal keels,
or rows of nodose prominences; the colour of the
shell being dark brown or blackish, upon which
are spots and streaks of yellow, and the soi't parts
having likewise a similar coloration. While in
young individuals the hinder border of the
carapace is strongly serrated, in the adult it
becomes nearly smooth. This species attains
length of nearly 9 inches at the present day, but

fossil examples found in the Pliocene rocks of Northern India were still largei
These fossil specimens lived with numbers of mammals belonging entirely to
extinct species. There are four other species of the genus, ranging over Malay ana.
Southern China, and Japan.

Sait-Water The last representative of the group with a smooth palate anc

Terrapin. carnivorous habits is the North American genus Malacoclemmys,
distinguished from the last by the head being covered with continuous skin, an-
by the groove formed on the plastron by the junction between the humeral am
pectoral shields being situated in advance of the entoplastral bone. While two
the species inhabit the valley of the Mississippi, the salt-water terrapin
terrapin) is a frequenter of the salt-marshes of the Atlantic Coast. The latter
has an oval and much depressed carapace, which attains a length of nearly 7
inches, and is characterised by the great width of the first and second vertebral
shields ; its general colour being either olive, w T ith black concentric lines, or




I'PPKIt SURFACE OK CARAPACE OP
HAMILTON'S TERRAPIN.



TERRAPINS.



73



uniform blackish. The plastron is yellowish or reddish, with variable black
markings.

It is this species that generally forms the celebrated New York dish known as
terrapin; but it would seem that other species are also used, as the following account
refers to terrapins taken high up the rivers. The best terrapins go by the name of
"diamond-backs," and do not generally exceed some 7 inches in length, although they
may rarely measure as much as 10 inches, but all terrapin of larger dimensions
belong to the inferior kinds, ordinarily designated " sliders." According to Mr. W.
M. Laffan, " terrapin are caught all the way from Savannah and Charleston to the
Patapsio River at Baltimore, but the genuine diamond-back belongs only to the
Upper Chesapeake and its tributaries. The majority of the sliders are brought to
Ualtimore from the James River. The terrapin-catchers make from five to twenty
dollars per week, and they find the reptile, or ' bird,' as the l)on vivant calls it, by
probing the mud in the shallows with sticks. The terrapin is dormant, and when
found is easily secured. A 4-lb. terrapin taken about September 15th will
exist prosperously in a dark, cool place, without food or drink, until April 15th,
and (the dealers say) will gain two ounces in weight. After that time it gets
lively and active, and will take hold of a finger with great effusion and effective-
ness. The male terrapin is known as a ' bull,' and the female as a ' cow.' The
latter is much more highly prized, and generally contains about thirty eggs.
No dish of terrapin is thought complete without being garnished with these."
Formerly caught in shoals, the diamond-back has now become very scarce, and is,
indeed, in some danger of extermination. The terrapin furnished in hotels is
almost invariably " sliders," diamond-backs being sold to private houses only.

Painted The seven remaining genera of the family constitute a distinct

Terrapin, group, distinguished from the one including the six genera just men-
tioned by the circumstance that the broad front portion of the palate of the skull is

irked by one or two longi-
tudinal ridges, and likewise by
all the species being mainly or
exclusively herbivorous in their
diet. Among these, the large
and exclusively American genus
Chrysemys,with a dozen species,
of which the painted terrapin
(C. pictct) is one of the best
known, belongs to a subgroup
of three genera, characterised
by the bony buttresses con-
necting the upper with the
lower shell being short or of
moderate size. From its allies
Chrysemys is distinguished by
the opening of the posterior

nostrils being situated between the eyes, and by the entoplastral bone being-
situated in advance of the groove on the plastron formed by the junction of the




PAINTED TERRAPIN.



74



TORTOISES AND TURTLES.



Batagurs.



humeral with the pectoral shields. The painted terrapin of Eastern North America,
which attains a length of 6 inches, and has a much depressed shell, takes its nan if
from its brilliant coloration. Thus, the carapace is olive or blackish, with yellow
lines bordering the shields, and its marginal shields red, with black concentric or
crescentic markings; while the plastron is yellow, sometimes with small streaks
of black on the middle line, and the bridge red, with black markings. The soft
parts have a brown or blackish ground-colour, with lighter bands, which are yellow
on the head and red elsewhere.

Eyed and Chinese The eyed terrapin (Morenia ocellata), from Burma, together with
Terrapins. an allied species from Bengal, constitute a genus distinguished from
the preceding by the aperture of the posterior nostrils opening behind the line of
the eyes. The typical species, in which the shell measures nearly 9 inches in
length, takes its name from the eye-like black spots ringed with yellow which
adorn each shield of the back portion of the carapace. On the other hand, the
Chinese terrapin (Ocadia sinensis), which is the sole existing representative of its
genus, differs from Chrysemys in having the entoplastron intersected by the groove
formed by the junction between the pectoral and humeral shields. The genus is
of special interest as being represented by extinct species in the upper Eocene
strata of the south of England and the Continent.

The remaining members of the family, which are arranged under
four genera, and may be collectively known as batagurs, are exclus-
ively confined to India, Burma, and the Malayan region. They comprise the

largest fresh- water representatives of the
family, and are readily characterised by
the great development of the vertical bony
buttresses connecting the carapace with
the plastron, which project as walls within
the shell, so as partially to divide it into
compartments. Of the four genera,
Cachuga, which is represented by seven
species from India and Burma, is readil
recognised by the great elongation of
fourth vertebral horny shield of tl
carapace, which extends over four or
of the underlying neural bones. Tl
smaller members, such as Smith's bat
(G. smithi), and the black - and -
batagur (C. tectum), of the Ganges and
Indus, are characterised by the fourth
vertebral shield terminating in front in a
narrow point. Whereas the former of
these lias a depressed and feebly keeled
shell, the latter, especially when young, lias
the carapace much vaulted, and the tliiid
M itcbral shield produced behind into a conical elevation forming the highest part
of the shell. The name of black-and-yellow batagur is derived from the irregular





UPPER SURFACE OF CARAPACE OF SMITH'S
BATAOTTR ($ Tlftt. Size).



BIG-HEADED TORTOISE. 75

! black patches on the bright yellow plastron; the carapace being brown. I have
taken specimens of this pretty little batagur, which does not exceed 8 inches in
length and is generally much smaller, near the fort at Calcutta. Like the under-
mentioned dhoiigoka, it occurs fossil in the Pliocene deposits of Northern
India. The larger species of the genus, such as the Indian dhongoka (C. dhongoka),
which grows to over 14 inches, has the fourth vertebral shield broad in front,
instead of being narrowed to a point. The three remaining genera, Callagur,
]]<it</gur, and Hardella, differ from the preceding in that the fourth vertebral
shield of the carapace is not longer than the third ; but it will be unnecessary to
point out the features by which they are severally distinguished. The largest of
all is the true batagur (Batagur lasca), in which the carapace measures upwards
of 20 inches in length.

All the batagurs are exclusively vegetable feeders, and the larger species are
thoroughly aquatic in their habits, spending by far the greater portion of their
time in the water. They abound in the larger rivers of India and Burma, where
their huge shells form conspicuous objects as they rise to the surface to breathe.
Describing the habits of a captive specimen, Dr. John Anderson states that when
it rose to breathe "its nostrils were simply protruded above the surface of the
water, and retained in that position for about half a minute, during which it made
a long expiration, followed by a deep inspiration, the creature then slowly
subsiding, tail-backwards, to the bottom. The animals, unless they were much
irritated, never attempted to bite, but, when so treated, they sluggishly seized any
object put in their way, holding it between their jaws with considerable tenacity,
at the same time withdrawing the head into the shell. They moved about on
the ground with considerable agility, supporting their heavy bodies erect on their
legs, like a land-tortoise." Another species will occasionally snap, when, owing to
the friction of its serrated jaws against each other, a peculiar kind of barking
sound is produced. Batagurs are eaten in Lower Bengal by some of the inferior
castes of Hindus, and are kept for this purpose in tanks.

THE BIG-HEADED TORTOISE.

Family PLATYSTERNID^E.

This extraordinary creature
(Platy sternum megacephalum), which
is an inhabitant of the south of China,
Siam, and Burma, is the sole repre-
sentative, not only of a very remark-
able genus, but likewise of a distinct
family, which appears to be to a great
t'xtcnt intermediate between that of
the tortoises and that of the snappers.
Tlie most peculiar feature about this
tortoise is the disproportionately

J SIDE VIEW OF SKULL OF BIG-HEADED TORTOISE.

large size of its head, in which the (From Boulenger).




7 6



TORTOISES AND TURTLES.



beak is much hooked; and an examination of the .skeleton will .show that' the
temporal fossae of the skull differ from those of all the members of the preceding
family in being roofed over with bone, as in the following family of the snappers.
Moreover, the tail resembles that of the latter in its great length, and also in the
circumstance that the articular surfaces of most of its vertebrae have the cup
behind and the ball in front, whereas in the tortoise family just the reverse of
this arrangement occurs. On the other hand, the carapace resembles that of the
latter, and differs from that of the snappers in the absence of a rib-like process
from its posterior angles passing backwards beneath the marginal bones. The




THE BIU-HEAUEL) TORTOISE (\ liat. Size).

carapace is characterised by its extreme depression and oval form ; while tl
plastron is of moderate size, and connected with the carapace solely by ligament,
so that bony buttresses are totally lacking. The head is covered with a continuous
horny shield, and the hooked jaws are of great power. The toes are of moderate
length, and but slightly webbed ; all, save the fifth in the hind-foot, bring I'nrnislied
with claws. The long and cylindrical tail becomes compressed at the end, and is



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 9 of 62)